The minimum size of the armored belt for aerated concrete. Resistance to loads with armored belt on aerated concrete

Are you building a cottage or a house from aerated concrete? You will definitely come across the question - what is an armored belt and why is it needed? You will find the answer to this question in our article. We will also tell you about how to arrange an armored belt in a house made of aerated concrete.

Why is it necessary to reinforce

What is an armored belt on aerated concrete. This is a belt-type structure made of reinforcement and concrete laid along all external and internal walls. It is intended to increase the strength of walls and foundations. In the design of the house, an important and responsible area, especially in houses that are built from block wall materials. This applies to walls and foundations.

An armored belt for a house made of aerated concrete blocks must be done not only around the perimeter. All internal walls and partitions must be connected to a common structure with external walls. Only this execution will give the structure of the house rigidity and strength.

Why do we need an armored belt for aerated concrete walls? Aerated concrete blocks material is not durable. In order to withstand the loads from seasonal heaving of the soil, the weight of floor slabs, roofs and a lot of other loads and the effects of external factors, the strength of the aerated concrete wall is not enough.

Kinds

According to their purpose and arrangement, the armored belts are conditionally divided into the following:

• Under the roof mauerlat
• Under floor beams
• Under floor slabs
• From brick on aerated concrete
• Under the block foundation
• On the foundation

The last two are a big separate topic. Consider how reinforcement is performed on the walls.

Reinforcement methods

There are several ways to make an armored belt for aerated concrete. The easiest, but not the cheapest, is to buy ready-made blocks in the form of a tray. The cost of a U-shaped block with a length of 500 mm varies, depending on the width and manufacturer, from 270 to 370 rubles per piece, excluding delivery. They can be installed on the outer walls, and on the partitions inside you still have to make formwork.

The most popular way is when a 100 mm thick block, 50 mm insulation, reinforcing cage and formwork are placed along the edge of the outer wall. In this design, the thickness of the armored belt for aerated concrete will be 150 mm less than the thickness of the wall, and the height is equal to the height of the block.

For houses that are supposed to have an external cladding, it is better to use a completely formwork pouring method with mandatory insulation of the outer side of the walls around the entire perimeter. Shields are installed from the outside, then 100 mm of insulation, a reinforcing cage and formwork along the inner wall. On internal walls and partitions, the formwork is placed without insulation. The height of the armored belt for aerated concrete in this case will be equal to the height of the formwork, but not less than 200 mm. The width is 100 mm less than the wall thickness. But not less than 250 mm along the bearing walls. By partitions, by their thickness.

Another view is an armored belt made of bricks on aerated concrete walls. It is carried out mainly on one-story houses and outbuildings with a pitched roof. Reinforcement in this case is done between rows of brickwork. A masonry mesh with a cell of 50 * 50 mm and a bar thickness of 4-5 mm is used for reinforcement. The mesh is laid in each row, a solid backing brick of grade not lower than M - 100. This armored belt is good for gable roofs, as it allows you to change the height of the wall and overlay fillies, rafters and a support board.

Reinforcement materials

The following materials are required for the construction of a reinforced concrete armored belt:

1. Shields for formwork;

• Edged board 25*100-150 mm (inch).
• Bar 50*50.
• The film is polyethylene.
• Fasteners: nails 70 - 100 mm, self-tapping screws 90 - 100 for fixing the formwork to the wall.

Laminated formwork plywood is better suited for the manufacture of formwork, but not everyone is ready to buy it. Expensive.

2. Reinforcement for the armored belt of a house made of aerated concrete is used only periodic (finned) with a diameter of at least 10 mm - the main longitudinal rods, and 6-8 mm smooth (round timber) on the crossbars that form a three-dimensional structure.

• knitting wire;
• Disc clamps for fittings. Size - according to the diameter of the main reinforcement.

3. Concrete grade 200 per 1 cubic meter.

• Cement M-400 - 286 kg.
• Washed granular sand - 795 kg.
• Crushed stone fraction 10-20 - 1080 kg.

It can be 20-40, but if you interfere manually, without a concrete mixer, then it is harder to work with a large one, when mixing and when tamping.

Ratio 1.0:2.8:3.8. Calculate the total amount of concrete according to the formwork. The calculation of the armored belt for an aerated concrete house must be done according to the actual dimensions of the house and the resulting volume of formwork

4. Insulation. Extruded polystyrene foam 50 or 100 mm thick

Important: if the insulation is installed immediately after the formwork, it must be fixed so that after the dismantling of the panels, the insulation does not fall off. To do this, you can pierce and tie it with wire to the armature, you don’t need to do this. You need to fix it by piercing the insulation with a special plastic dowel. After removing the formwork, it will securely hold the insulation sheets.

Required Tool

For the production of work on the installation of an armored belt, you will need:

1. Hacksaw
2. Electric circular saw.
3. Screwdriver.
4. Perforator
5. A hammer.
6. Shovels and a container for the preparation of concrete (leg)
7. Buckets and rope for lifting ready-mixed concrete.

Nuances of reinforcement

The manufacture of an armored belt on aerated concrete for floor slabs is done after the first floor. The last floor is rarely covered with slabs. It is carried out along the inner edge of the supporting wall. The slab should rest on the armored belt with a plane of 12 - 15 cm. The reinforcing cage is made reinforced. In the horizontal plane, two levels of three or four bars are made, depending on the thickness of the monolithic section. But the plates, especially if conventional non-lightweight ones are used, should lie on two bars. That is, to strengthen the inner side of the armored belt.

The armored belt, in a house made of aerated concrete, does not need to be reinforced under wooden floors. The cover is light. You can do it using standard blocks - trays, and formwork.

Metal beams for ceilings on an armored belt, for an aerated concrete house, are installed only using welded linings three times the area of ​​​​the sole of the beam. If the size of the support sole of the beam is 100 * 200 mm, then the lining should be 300 * 200 mm in size.

Particular attention should be paid to the device of the armo-belt under the Mauerlat in the house of aerated concrete. It is equipped with fixtures for attaching the supporting beam of the rafters. Lay, before pouring concrete, a wire of 6 mm. They make it U - shaped, inserted under the reinforcement in increments of 1 meter. The length of the free ends should be sufficient to tie the Mauerlat. For fastening the Mauerlat, threaded studs with a diameter of 12-14 mm are also used. To install them, you need to drill holes in the top row of blocks with a stud installation step. Screw nuts onto the studs, put enlarged washers and install in the drilled holes. Wrap the thread that is higher than the armored belt with paper or tape. so as not to clog with a solution when pouring. The length of the studs should be 5 cm more than the thickness of the armo-belt and Mauerlat, excluding the depth.
It is possible to securely install a roof without an armored belt, but this will require other devices that do not guarantee lower cost and greater reliability. This is the answer to the question "Do I need an armored belt for a one-story house?". Does this house need a roof?

Places of reinforcement

When assembling the reinforcing cage, special attention should be paid to the corners and junctions of the inner walls and partitions to the outer perimeter. In these places there should be no gaps and joints. The armature must bend. If the frame is not made on the wall, which is more convenient, then it should be made in straight sections convenient for installation. After installation in the formwork, connect the corners and junctions with ready-made L-shaped elements. The length of the overlap should be at least 50 cm when knitting with wire. When welding, the length of the weld should be at least 20 diameters of the welded reinforcement.

As already mentioned, reinforcement requires an armored belt on which reinforced concrete floor slabs will be laid.

Very important: when building a house, many people want to make a big window, from the first floor window sill to the second floor ceiling. "Second Light" is certainly beautiful. But with the wrong approach, this is a bomb that will destroy the house exactly on this window. Such a window should be considered at the foundation design stage. The interfloor armored belt torn in the place of the window will not work properly, and it is necessary to compensate for the loss of strength with some structures. And this is a job for a good designer.

Pouring an armored belt on aerated concrete is fundamentally no different from pouring on other materials. The design is simple, and work without the use of mechanisms is heavy, especially on the second and higher floors.

Armopoyas (reinforced reinforced concrete belt) aka seismic belt- a very strong monolithic strip along the perimeter of the building and load-bearing walls made of aerated concrete.

Tasks of the armored belt - significant strengthening of load-bearing walls to increase their bearing capacity, to avoid cracks and other deformations due to uneven shrinkage of the building, roofing, wind and other loads.

The armored belt securely fastens aerated concrete blocks, evenly distributes the load and creates structural rigidity.

Ideally, the geometry, reinforcement and composition of the concrete of the armored belt is determined by calculations.

Usually the width (thickness) of the armored belt equal to the width of the wall, 200-400mm, and the recommended height is 200-300mm.

But it would be wiser to make the width of the armored belt a little thinner than the wall, so that there is a reserve of space for insulation, to reduce cold bridges. Extruded polystyrene foam (EPS) is best for this business, as it isolates heat perfectly. There is also the option of pouring the armored belt into ready-made aerated concrete U-blocks, but see more about this later in the text.

1. With uneven shrinkage of the house, with seasonal heaving of the soil, during earthquakes, the armored belt holds the geometry of the building.
2. Armopoyas can align walls horizontally.
3. Giving rigidity to the entire building of aerated concrete.
4. Local loads are distributed evenly on load-bearing walls.
5. The high strength of the armored belt allows you to attach all critical structures to it, for example, a Mauerlat.

Mauerlat must be firmly attached to the load-bearing walls with studs and anchors. The rafter system itself, the weight of the entire roof, snow and wind loads create a significant bursting force that can break unreinforced walls. The armored belt under the Mauerlat solves this problem, and it will be performed in the same way as under the ceiling.

1. The frame of the belt reinforcement must be continuous.
2. Armopoyas should be on all load-bearing walls.
3. The overlap of the longitudinal reinforcement is at least 800 mm.
4. The frame is made of two rows of reinforcement, two rods each.
5. The minimum thickness of the longitudinal reinforcement is 10 mm.
6. It is advisable to use long (6-8 meters) reinforcement bars.
7. The diameter of the transverse reinforcement is 6-8 mm.
8. Step of transverse reinforcement - 200-400 mm.
9. Reinforcement on all sides must have a protective layer of concrete of at least 5 cm.
10. The longitudinal and transverse reinforcement is connected to each other with a knitting wire.
11. At the corners, the longitudinal reinforcement must be bent, and try to overlap further from the corner.
12. The frame must be strictly horizontal.

Calculate the distance between the reinforcement bars according to the thickness and height of the armored belt, taking into account the protective layer of concrete, at least 5 cm on each side.

Do-it-yourself armored belt for aerated concrete (video)

Scheme of reinforcement of corners and junctions of the armored belt

Armo-belt insulation

The armored belt is a very serious "bridge" of cold, through which most of the heat escapes, and on which condensation forms from the inside of the armored belt. And to avoid this, it is necessary to insulate the outer side of the armored belt with aerated concrete, or polystyrene foam or polystyrene. Expanded polystyrene is more preferable. So in advance you need to provide space for insulation, filling in the armored belt with an indent from the outer edge of the wall.

Insulated armored belt for aerated concrete

What brand of concrete to fill the armored belt

For pouring the reinforced belt on aerated concrete, concrete grade M200-M250 is used. It can be brought ready-made with a mixer from the factory, or you can make it yourself.

Proportions for concrete grade M200: cement M400, sand, crushed stone (1:3:5). Proportions for concrete grade M250: cement M400, sand, crushed stone (1:2:4).

There should be a minimum amount of water in concrete, and to give plasticity, use a plasticizer.

The water-cement ratio should be in the range from 0.5 to 0.7, that is, 5 to 7 parts of water per 10 parts of cement.

Adding too much water to concrete makes it less durable.

To remove air bubbles from concrete, it should be vibrated with a special building vibrator, or the liquid concrete should be intensively and for a long time pierced with a piece of reinforcement.

Concrete must be poured into the formwork at one time so that it is monolithic (inseparable).

Aerated concrete is an excellent alternative to brick. However, unfortunately, the value of the strength index of aerated concrete blocks is much lower. The material does not hold fasteners on its surface well.

Masonry of aerated concrete blocks has its own characteristics:

1. The construction of walls must be carried out on a solid foundation.
2. In the process of work, it is necessary to regularly check the evenness of the structure.
3. Along the entire perimeter of the building, the walls should be strengthened with a reinforced belt made of reinforced concrete.

When conducting construction work in violation of technological rules, cracking of blocks may occur under the influence of roof pressure.

The meaning of the armored belt

A reinforced belt is a monolithic structure located around the entire perimeter of the building. Armopoyas protects the walls of the house from destruction and deformation under the influence of loads. The technology of strengthening the wall surface of an object involves laying a relief belt between the ceilings of each floor and at the place of roofing.

To ensure the functionality of the armored belt, its structure should be:

1. continuous.
2. Ring style.
3. closed.

The main components of the armored belt:

• Armature frame.
• Concrete mix.
• Formwork or blocks.

The purpose of the design is:

• In the distribution of the bearing load from additional floors or roofing on the walls in order to give them strength.
• In protecting the foundation and walls from cracks.
• In increasing the spatial rigidity of the building.

The design ensures the strength and reliability of load-bearing walls, increases the resistance of the structure to the effects of wind, temperature changes, seismic vibrations, shrinkage of the soil and the construction site itself.

Armo-belt dimensions

The dimensions of the armored belt depend on the design features of the building material to which it is necessary to attach it. The wall can be internal or external. For each category, builders consider their specific requirements regarding the size of the structure.

1. The internal structure is reinforced with an armored belt with a width value corresponding to the thickness of the wall.
2. When strengthening the house from the outside, the width of the protective belt should correspond to the width of the wall, excluding insulation and formwork.
3. The minimum value of the height of the structure corresponds to one hundred and fifty millimeters. This indicator cannot be greater than the width of the wall.

Options for creating an armored belt

It is possible to install an unloading belt for walls made of aerated concrete blocks in several ways:

1. With the help of wooden formwork.
2. Using extension blocks.

When comparing these two methods, it can be noted that it is technologically more difficult to equip walls with armored belts using wooden formwork. The second method, using additional blocks, is much simpler, but you will have to invest more money in it due to the use of expensive building material.

The unloading belt is not laid:

• Under a solid reinforced concrete structure.
• Under wooden floors, based on blocks.

In the case, it is enough to pour concrete pads five centimeters thick under the beams, playing a supporting role, which will reliably protect the building blocks from punching.

In reinforced concrete structures, there is no point in additional protection due to the uniform distribution of the load on the walls

Creating an armored belt using formwork

The formwork for the unloading belt is a wooden frame. It is made from scraps of boards fastened together on the outside.

After the complete assembly of the formwork, its lower part is attached to the wall with self-tapping screws, and the upper part - with transverse board ties with an interval of eighty to one hundred centimeters. The screed is necessary to give the structure reliability, otherwise, when pouring concrete, it can be deformed or crushed.

Prior to the construction of the structure, you should take care of acquiring the necessary building materials:

1. Edged boards, with a minimum thickness of three centimeters and timber 40x40 for the manufacture of formwork.
2. Nails for fastening the board structure to the wall.
3. Flexible wire to stiffen the structure.
4. Reinforcing bars with a diameter of twelve millimeters.
5. Expanded polystyrene for insulation.

Construction tools used:

1. Drill.
2. Hacksaw.

Formwork construction technology

The technological process involves the performance of work in several stages:

1. Preparation of wooden shields.
2. Laying a layer of polystyrene between the wall of the house and a wooden shield for insulation purposes.
3. Fastening the structure to the wall with self-tapping screws or long nails.
4. Additional fastening of elements of a wooden structure using self-tapping screws and wire.
5. Reinforcing cage assembly. Initially, the reinforcing pins should be laid inside the wooden shields. A flexible wire is used to connect to the reinforcement frame. It is not recommended to fasten the reinforcement to each other by welding due to the rusting of the material inside the concrete.
6. Filling with cement mortar.

Reinforcement

Reinforcement is made from reinforcement bars with a diameter of eight to twelve millimeters.

The principle of the process is:

1. In horizontal laying of rods.
2. In fastening them, they are overlapped with a flexible knitting wire around the entire perimeter of the wall.
3. In tying joints with rings of wire with a diameter of six millimeters.

Reinforcing bars should be knitted directly in the formwork. In finished form, the reinforcing cage is heavy. With a separate assembly of the structure, it will be difficult to lift and place it. Between the aerated concrete blocks and the frame of the unloading belt, it is recommended to lay a layer of stones or bricks.

1. Pouring concrete

When purchasing a dry concrete mix, it is necessary to use a material marking of at least M200.

In the absence of products of the required characteristics in the store, you can cook it yourself, using the following proportions in the ratio of components:

• Crushed stone - 4.8 parts.
• Cement - 1 part.
• Sand - 2.8 parts.

To increase the density of the composition, crushed stone can be replaced with gravel. After mixing the dry elements, water should be added in small portions, the amount of which should correspond to twenty percent of the total amount of the mixture.

The concrete pouring technology provides for work performance standards that, in order to obtain the desired functional result, should be performed:

1. Pouring must be carried out in one cycle without interruptions, preventing partial drying of the concrete layer.
2. It should be avoided in the solution for pouring bubbles with emptiness, which in the future, when the mixture dries, will reduce the strength characteristics of the structure.
3. After pouring, it is recommended to compact the concrete using a perforator with a special nozzle. Also, to eliminate voids in the solution, a vibrating machine is used, and in its absence, air bubbles will have to be removed by baying the solution with fittings.

2. Construction of the unloading belt using blocks

Formwork can be not wooden structures, but U-shaped aerated concrete blocks. A prerequisite for such a building material is the presence of an internal cavity, which is necessary for laying the frame of reinforcement and pouring concrete.

Tray type blocks are stacked the same width as the walls. It is convenient to arrange such a belt to the outer walls due to its additional insulating function, while excluding the formation of "bridges" of cold.

3. What will be required

The method is simple and requires the prior purchase of building material - additional blocks ten centimeters thick. Before buying, you should calculate the required amount of material based on the planned height of the structure and the perimeter of the object.

The process of manufacturing the construction of the armored belt using additional blocks

1. Installation of additional blocks on the wall in the usual manner.
2. Reinforcement of the central part of the building material.
3. Pouring with cement mortar of the resulting structure.

Brick armored belt

The loading belt can be constructed using brickwork reinforced with reinforcing mesh. It is less reliable than concrete and is applicable only for small outbuildings. To increase the strength indicators of a brick structure, the use of reinforcement or welded metal mesh is recommended.

Features of the building:

1. When using a reinforcing mesh with a cross-sectional diameter of five millimeters, it is recommended to lay it through four rows of bricks.
2. The width of the structure must correspond to the thickness of the wall of the building being processed.
3. The height of the structure depends on the type of building material of the walls of the house and on the type of roof. The average construction size for a wall of aerated concrete blocks is forty centimeters.

Strengthening walls with bricks with built-in reinforcing mesh cannot fully replace giving reliability to structural elements using a reinforced concrete counterpart.

Armo-belt insulation

The most important feature of aerated concrete is its low thermal conductivity, which ensures the absence of a freezing factor for a structure built from it, even at the lowest ambient temperature. Therefore, when constructing a reinforcing structure, it is important that it does not violate the thermal insulation properties of the house.

In the cold season, as well as during periods of sharp temperature changes, condensation may occur on the reinforced belt. In order to avoid this phenomenon, it is recommended to carry out work on the insulation of the structure.

Expanded polystyrene, polystyrene and mineral wool can be used as insulating heat-insulating elements. In some cases, aerated concrete blocks with partitions are used. When using mineral wool, a small ventilation gap should be left between the insulation and the facing surface.

Tips for organizational work on the insulation of the object:

1. When constructing a structure for the purpose of its subsequent insulation, it should be performed with an indent from the outer edge of the wall, and not over its entire width.
2. The minimum width of the unloading belt should be twenty centimeters when using monolithic concrete and twenty-five centimeters when using bricks.
3. The resulting free space after pouring the armored belt should be filled with insulation and closed with a foam block, pre-cut in accordance with the desired dimensions.

1. When pouring with a cement composition, care should be taken that the elements of the reinforced mesh do not touch the walls of the formwork.
2. To increase the functionality of the armored belt, the reinforcement frame is installed on the surface using a level.
3. The strength of concrete after it is poured is facilitated by its periodic moistening, especially in hot weather. It is recommended to moisten the structure every day for five days. The best effect is achieved when the moistened surface is covered with a plastic film.
4. It is possible to remove the formwork in a week, however, it will function as intended only after two weeks, when the cement mixture has completely solidified.
5. If you plan to insulate the unloading belt, then you should not do it flush with the wall. Experts recommend moving the formwork inward with the further goal of filling the resulting niche with insulating heat-insulating material.
6. There is no need to spend money on a reinforced belt if there is a solid soil not saturated with water under the foundation, brick walls, and also when building a one-story house with wooden beams rather than reinforced concrete panels.

The armored belt in a house made of aerated concrete, brick (other block materials) during construction serves as additional protection for walls and other load-bearing structures from deformation and movement. In other words, this belt is nothing more than a reinforced concrete structure designed to strengthen the walls and foundations of the house from various loads that arise under the influence of both external and internal factors. External factors include the impact of wind, ground movements, the features of the site relief and, of course, the seismic activity of the earth. Internal factors include the redistribution of load from load-bearing elements, the connection of columnar elements (foundation), the installation of additional fasteners and structures.

For a more detailed study of the issue, we will consider the process of installing an armored belt using the example of a house made of aerated concrete. However, this technology is applicable to other types of houses, where the walls can be made of bricks, expanded clay blocks and any other block materials. But, first of all, we will determine the factors acting on the walls and figure out why an armored belt is needed in this or that case.

Why do you need an armored belt in the house

Scheme of a house made of block materials

To understand the principle of operation of a reinforcing protective structure, consider it as part of building a house. Any stone or block material works better in compression than in tension. Tensile and torsion loads can arise both as a result of the settlement of the building, when the soil is heaving at the foundation, and for other reasons. It can also be caused by an incorrect calculation of the bearing capacity, as a result of which the walls in different areas will receive both compressive and more critical tensile loads. These masonry sections may not be structurally ready for them. As a result, the walls will crack. By adding reinforcement with concrete at the top of the masonry between floors, we will additionally protect the walls from destruction.

Take for example a house made of aerated concrete and consider the scheme. In the lower part, it is almost always performed, which is still the same protective belt. Properly executed warping copes well with loads, so at this level there should be no problems. Using an interfloor armored belt, we add reinforcement to the structure that can cope with stresses. At the same time, the wall itself becomes more rigid and conditionally works like an I-beam. The monolithic belt also resists lateral loads from the wind and bursting loads from the roof at times better. In the sum of all these properties, the seismic resistance of the house also increases, which is a mandatory requirement for any residential building in seismic zones. We considered a multi-storey scheme, however, the armored belt is also applicable in a one-story house with or without an attic. In this case, in conjunction with the foundation, a Mauerlat belt is used.

The armored belt also redistributes point loads well. This is especially important for materials that are not ready to work with local point loads - these are gas silicate blocks and other similar materials. Therefore, in a house made of aerated concrete, it is imperative to carry out reinforcement for reinforced concrete floor slabs. A similar principle of redistribution of loads has a wooden base for rafter legs. But, at the same time, in order to qualitatively fix the Mauerlat to a structurally weak wall, an armored belt is needed. The under-roofing belt will increase both the structural rigidity of the walls, and will also solve the issues of fixing the roof structures.

Calculation of the reinforced belt

Before starting the necessary work on the installation of an armo-belt on the walls of the house, under floor beams or Mauerlat, it is necessary to make load calculations and determine the geometric characteristics of the protective element being erected.

Each specific option requires an individual calculation depending on the material of the floors, the type of belt beam. If we generalize and take as an example a standard box of aerated concrete with, then the manufacture of an armored belt will take a minimum of costs and materials.

According to generally accepted practice, the thickness of the belt is taken to be the same as the thickness of the wall itself, despite the fact that its height is on average set from 150 to 300 millimeters. The structure serves as a sample of the minimum reinforcing cage - two rods with a diameter of 10-12 millimeters from below and from above, fastened with frames from a rod of 6-8 millimeters.

Armopoyas - the main stages of manufacturing

Rebar frame

The assembly of the frame begins with the installation of reinforcement on the top of the wall. When laying, it is necessary that it subsequently be sunk into concrete at least 40 mm from the outer boundaries of the monolithic belt. When working with aerated concrete, for convenience, control sections of reinforcement can be driven into it. And already to the segments, attach the frame with a given indent from the top of the masonry. To tie the reinforcement together, you will need a soft knitting wire. To set the dimensions of the frame, it is recommended to create a square of four pins or bend it from a solid rod (transverse clamp). These clamps are primarily attached to segments driven into the wall at a certain interval - usually 250-300 millimeters. If you do not drive in the control pins, then you will need special linings - clamps to raise the frame itself. Therefore, consider the feasibility of a particular method. Having completed this work, we proceed to the fastening of the reinforcement.

The lower row of longitudinal reinforcement is wound into frames - clamps and connected with wire. The upper row is attached in the same way (the longitudinal reinforcement must be inside the clamp). As discussed above, the required minimum is two fittings from below and two from above. For additional rigidity, the amount of reinforcement and the frame configuration can be changed. Naturally, this will affect material costs. But if it is necessary, the calculation should not be neglected. We also note that the length of segments or solid squares (transverse clamps) is related to the thickness of the armored belt. For example, the thickness of the belt is 300 millimeters, then the dimensions of the transverse clamps are 220 × 220 millimeters (taking into account that the height of the belt is also 300 millimeters). That is, we leave indents from the edges of at least 40 millimeters.

Reinforcement of belt corners

formwork

Consider formwork. What options for installing a monolithic belt in a private house can be:

• Using factory or homemade U-blocks as formwork.
• Formwork made of aerated concrete blocks of small thickness.
• Formwork from .
• Shield collapsible formwork made of boards or plywood.

	Aerated concrete U-blocks are used as a fixed formwork for the installation of reinforced monolithic lintels blocking openings in walls and partitions, as well as for the installation of strapping monolithic reinforced belts that impart spatial rigidity to the entire building and redistribute the load from the ceilings. U-shaped blocks are fixed formwork elements for reinforced concrete. The diameter of the reinforcement and the class of concrete for filling the U-block are selected according to the calculation, depending on the perceived load. When choosing these elements as formwork, consider how the concrete tape is insulated. It is advisable to insulate the block from the outside, but if this is not possible in certain cases, put the insulation inside (given the internal factory dimensions, this is not the best option).
	The formwork of aerated concrete blocks of small thickness with a possible thickness of the outer wall of 375-400 millimeters can have the following structure: Outside - a block with a thickness of 100-150 mm. Next in order - we insulate the armored belt to cut off the bridge of cold. Instead of extruded polystyrene foam with a thickness of 50-100 mm, mineral wool of increased density, which is used in the "wet facade" technology, can be used. Armature frame. On the inside of the wall, blocks with a thickness of 50-100 millimeters are used as fixed formwork. The remaining space is filled with concrete. The advantages of this type of formwork include the speed of its installation. To strengthen the structure, you can additionally use screeds from bars or fittings connecting the indoor and outdoor units.
	Expanded polystyrene formwork performs several functions: it gives shape to concrete, protects it from spreading and subsequently serves as an excellent insulation. Advantages of this formwork method: Ease of formwork assembly. Ready-made blocks are produced, including corner joints. High installation speed. The installation of reinforcement is facilitated, because there are special grooves for it. It is easier to control the dimensions of the concrete tape. Concrete will harden in the formwork, which will protect it from rapid drying, sudden temperature changes. Extruded polystyrene foam is a waterproofing material. It may seem that this technology is very expensive. But if we take into account the cost of insulation, the cost of assembling and dismantling conventional wooden formwork, then the difference becomes insignificant. Alternatively, this formwork can be made not from factory blocks, but independently from expanded polystyrene. But this will be more labor intensive.
	Shield collapsible formwork made of boards or plywood for an armored belt in an aerated concrete house is the most time-consuming to manufacture. At the first stage, you need to make shields from the boards. To do this, put them together and connect them with wooden blocks and nails. At the second stage, ready-made shields are installed along the perimeter of the future reinforced belt. The concrete mortar will create pressure on the formwork walls, so in order for the formwork not to move apart, it is necessary to fasten the entire structure with clamps.

pouring concrete

In general, this stage should not cause difficulties. The only inconvenience is the delivery of concrete to the very top of the wall. The quality of concrete should not be lower than . When making a mortar yourself using M-500 cement, the following proportion will help - a bucket of cement / three buckets of sand / five buckets of crushed stone. It is recommended to use thick concrete - so it does not put much pressure on the formwork. It should not be forgotten that the concrete must be properly compacted. Bay concrete, cover it with a film. Thus, you will reduce the evaporation of moisture. It usually takes about two days for the concrete to fully set, after which the formwork can be removed (provided that it is collapsible).

Video: armored belt in aerated concrete house

This video demonstrates the installation of a Mauerlat reinforced belt on aerated concrete walls. The formwork in this case is made of plank boards. When viewing, pay particular attention to the rebar connections at the corners. It is better to additionally connect the studs for fixing the roof with the frame reinforcement and not waste energy on useless reinforcement in a fragile gas silicate block.

As a conclusion, we note that the armored belt in a house made of aerated concrete and any other block material is waterproofed before further stages of work. Whether or not it makes sense is up to you. Naturally, considering the foundation belt, it must in any case be covered with insulation, since there is moist soil nearby. With belts above the foundation, with the correct construction of the walls, there should be no moisture in the concrete. But still, it will not be superfluous to separate the Mauerlat belt with waterproofing from the wooden structures of the truss system.

Any developer, having decided to build a house from aerated concrete, is faced with the need to manufacture an armored belt (it is also called a seismic belt). Armopoyas on aerated concrete is a monolithic reinforced concrete tape, poured around the entire perimeter of the walls (between the first and second floors, etc.). This element is necessary for uniform distribution of the load and connection of the walls together. This reduces the risk of cracking due to uneven shrinkage of the building. Also, the armored belt is laid under the Mauerlat when constructing the roof.

Maxim Pan FORUMHOUSE user, Moscow.

It is impossible to fasten a beam (Mauerlat) directly to aerated concrete on studs. If this is done, then over time, under the influence of wind load, the fasteners will loosen. When constructing an attic floor, an armored belt on aerated concrete with a wooden floor will redistribute the point load from the beam to the entire wall.

An illustrative example is a forum member with a nickname madmax, which fully answers the question, when you need an armored belt in a house made of aerated concrete . He did not have time to pour an armored belt under the Mauerlat, and the house went into "winter". Already during the cold weather, the arched openings under the windows in the house cracked exactly in the middle. At first, the cracks were small - about 1-2 mm, but gradually they began to increase and for the most part opened up to 4-5 mm. As a result, after the winter, the member of the forum filled in a belt of 40x25 cm, in which, before pouring the concrete solution, he installed anchors under the Mauerlat. This solved the problem with growing cracks.

mad-max FORUMHOUSE user

I would like to add to this that the foundation for my house is tape - monolithic, the soil is stony, there were no movements in the foundation before I started building the house. I believe that the reason for the appearance of cracks was the lack of an armored belt under the Mauerlat.

An aerated concrete house, and even more so a house with two floors, needs an armored belt. When making it, remember this rule:

The main condition for the correct "work" of the armored belt is its continuity, continuity and looping around the entire perimeter of the walls.

There are several options for installing an armored belt in an aerated concrete house. The manufacture of the armored belt begins with the calculation of its cross section and the choice of the type of formwork - removable or fixed, as well as the "pie" of the entire structure.

eyeonenow FORUMHOUSE user

I am building a house of aerated concrete with a thickness of 37.5 cm, with a brick cladding and a ventilated gap of 3.5 cm. I do not want to use special factory-made U-blocks for pouring the armored belt. I saw on our forum the following scheme when building a house, how to insulate an armored belt - a partition block 10 cm thick is installed on the wall block, then insulation (EPS) comes on, and a removable formwork is mounted inside the house. I also saw an option when the insulation is pressed close to the brickwork. With this scheme, a belt of greater width is obtained.

To understand which option to choose, let's turn to the experience of FORUMHOUSE experts.

44alex FORUMHOUSE user

I built a house of aerated concrete 40 cm thick. In my opinion, a ventilated gap between the wall and the cladding of 3.5 cm is not enough, it is optimal to leave a gap of 5 cm. If you look at the “pie” of the armored belt from the inside out, it was as follows:

• removable formwork;
• concrete 20 cm;
• EPPS 5 cm;
• partition block 15 cm.